Energetics and Mechanism of Conformational Transitions of Protein‐Like NIPAM‐Sodium Styrene Sulfonate Copolymers in Aqueous Solutions

Protein‐like and random NIPAM‐sodium styrene sulfonate copolymers of similar composition have been prepared by radical polymerization in water at temperatures above and below the LCST of PNIPAM, respectively. Thermal transitions of the copolymers in aqueous solutions have been studied by means of dynamic light scattering, viscometry, and high‐sensitivity differential scanning calorimetry. The phase separation or cooperative conformational transitions without phase separation were observed for the random or the protein‐like copolymers, respectively. Transition temperature, enthalpy, and heat capacity increment of the protein‐like copolymer differed insignificantly from those of the random copolymer of similar composition. The transition heat capacity increments of the protein‐like copolymers revealed that only 10–20% of their NIPAM links participate in the formation of a dense water‐free globule core. The coil–globule transitions of the protein‐like copolymers were described by the thermodynamic three‐state model according to the scheme “random coil?condensed coil?globule”, which is known to simulate the folding mechanism of globular proteins.

     

Anti-phytopathogenic sesquiterpenoid-xanthone adducts from potato endophytic fungus Bipolaris eleusines

A bioguided separation on the cultures of the potato endophytic fungus Bipolaris eleusines led to the isolation of two anti-phytopathogenic (Alternaria solani) sesquiterpenoid-xanthone adducts, namely bipolins I and J (1 and 2). Their structures were established via extensive spectroscopic analysis. Compounds 1 and 2 exhibit potent inhibitory activity against A. solani with MIC values of 8 and 16 μg mL⁻¹, respectively.

Two sativene sesquiterpenoid-xanthone adducts from potato endophytic fungus Bipolaris eleusines     

Interaction of oxalic acid with methylamine and its atmospheric implications

Oxalic acid, which is one of the most common dicarboxylic acids, is expected to be an important component of atmospheric aerosols. However, the contribution of oxalic acid to the generation of new particles is still poorly understood. In this study, the structural characteristics and thermodynamics of (C₂H₂O₄)(CH₃NH₂)_n (n = 1–4) were investigated at the PW91PW91/6-311++G(3df,3pd) level of theory. We found that clusters formed by oxalic acid and methylamine are relatively stable, and the more the atoms participating in the formation of a ring-like structure, the more stable is the cluster. In addition, via the analysis of atmospheric relevance, it can be revealed that clusters of (C₂H₂O₄)(CH₃NH₂)_n (n = 1–4) have a noteworthy concentration in the atmosphere, which indicates that these clusters could be participating in new particle formation. Moreover, by comparison with (H₂C₂O₄)(NH₃)_n (n = 1–6) species, it can be seen that oxalic acid is more readily bound to methylamine than to ammonia, which promotes nucleation or new particle formation. Finally, the Rayleigh scattering properties of clusters of (C₂H₂O₄)(CH₃NH₂)_n (n = 1–4) were investigated for the first time to determine their atmospheric implications.

Oxalic acid, which is one of the most common dicarboxylic acids, is expected to be an important component of atmospheric aerosols.     

4-Phenylpyrimidine monolayer protection of a copper surface from salt corrosion

4-Phenylpyrimidine (4-PPM) containing N heteroatoms can easily form compact and uniform layers on metallic surfaces. In this work, the protection of a copper surface from corrosion in 3 wt% NaCl by a 4-PPM layer was investigated by electrochemical impedance spectroscopy (EIS) and polarization methods. Under optimum conditions, the inhibition efficiency of a 4-PPM layer for copper corrosion reached 83.2%. Raman analysis in conjunction with calculations using density functional theory (DFT) based on the B3LYP/LANL2DZ basis set suggested that the 4-PPM molecule anchored on the copper surface via the N₁ atom to construct a uniform layer.

The efficiency of a 4-phenylpyrimidine monolayer optimally self-assembled on a copper surface against corrosion by a 3 wt% NaCl solution could reach 83.2%.     

Improved performance of optical phased arrays assisted by transparent graphene nanoheaters and air trenches

In this paper, high-performance optical phased arrays (OPAs) assisted by transparent graphene nanoheaters and air trenches have been designed and simulated. By directly locating graphene nanoheaters on silicon waveguides, heating efficiency is enhanced by 62.96% compared to conventional structures with 1 μm SiO₂ overlays, and is further enhanced by a factor of 200% by the presence of air trenches. Thanks to the high thermal conductivity of graphene, a record-high operation speed on the order of 200 kHz is realized. Power consumption for π phase shift is 4.65 mW, approximately half of that of the state-of-the-art OPAs. By introducing air trenches, thermal crosstalk is significantly reduced, resulting in an enlarged fill factor. In addition, a novel beam steering scheme in the θ direction is proposed. By applying a 30 mW heating power, a temperature gradient along antennas is generated and beam steering of 2.3° is achieved, satisfying applications such as long-range collision avoidance for autonomous driving.

Improved performances of optical phased arrays have been achieved assisted by graphene nanoheaters and air trenches.     

A synthesis and performance evaluation of a highly efficient ecological dust depressor based on the sodium lignosulfonate–acrylic acid graft copolymer

In this paper, a highly efficient and environmentally-friendly dust depressor was developed based on the sodium lignosulfonate–acrylic acid graft copolymer. Using the grafting ratio as an index, a three-factor and four-level orthogonal experiment was conducted to optimize the fabrication conditions of the graft copolymer. At a reaction temperature of 60 °C, feed ratio m_SLS–AA of 1 : 3, and FeSO₄·7H₂O content of 2.5%, the prototype produced the highest grafting ratio. The microstructure of the graft copolymer was measured using Fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance (¹H-NMR). Furthermore, the influence of glycerol and the JFC penetrant on the contact angle between the compound solution and coal powder was investigated. Finally, four formulas of dust depressor were selected based on the experimental results. The dust-control performance of the four dust depressors was then tested on a large-scale spray dust suppression simulation platform. The results show that after applying formula 1 at various distances from the spray field, the average dust reduction rates of the total dust (respirable dust) at each point increased. Compared to the water-spraying dust suppression technique, the dust concentration is significantly reduced after the graft copolymer dust depressor is applied.

In this paper, a highly efficient and environmentally-friendly dust depressor was developed based on the sodium lignosulfonate–acrylic acid graft copolymer.     

Y‐27632 simplifies the isolation procedure of human primary epidermal cells by selectively blocking focal adhesion of dermal cells

Primary skin epidermal cells isolation and in vitro expansion culture have been widely used for laboratory research and clinical applications. The conventional methods involving sequential enzymatic digestion of adult tissues have given low cell recovery rate and reduced cell viability. We report here an advanced method for human primary epidermal progenitor cells isolation from skin tissues including the Rho kinase inhibitor Y‐27632. Compared with traditional protocols, the current protocol is simple, easy, and faster; moreover, it gives a greater yield of integrin‐expressing epithelial stem cells. In addition, our new methodology does not require a separation of epidermis from dermis because the medium selectively blocks focal adhesion and growth of dermal cells. Importantly, the cells isolated from this method can maintain their regeneration potential and quickly reconstitute a mature human skin in vivo after grafting onto nude mice. In brief, we describe here a simple (one step) and serum‐free method for isolating primary epidermal stem cells from adult tissues. The isolated cells may be widely used for both laboratory studies and clinical application, especially in the field of tissue engineering and regeneration.     

Establishing a Research Agenda on Mobile Health Technologies and Later-Life Pain Using an Evidence-Based Consensus Workshop Approach

The rapid growth of mobile health (mHealth) devices holds substantial potential for improving care and care outcomes in all patient populations, including older adults with pain. However, existing research reflects a substantial gap in knowledge about how to design, evaluate, and disseminate devices to optimally address the many challenges associated with managing pain in older persons. Given these knowledge gaps, we sought to develop a set of practice-based research priorities to facilitate innovation in this field. We employed the Cornell Research-Practice Consensus Workshop Model, an evidence-based approach to generating research priorities. Sixty participants attended the conference, where stakeholder groups included older adults with pain and their caregivers, behavioral and social scientists, healthcare providers, pain experts, and specialists in mHealth and health policy. Participants generated 13 recommendations classified into 2 categories: 1) implications for designing research on mHealth among older adults (eg, conduct research on ways to enhance accessibility of mHealth tools among diverse groups of older adults with pain, expand research on mHealth sensing applications), and 2) implementation of mHealth technology into practice and associated regulatory issues (eg, promote research on ways to initiate/sustain patient behavior change, expand research on mHealth cybersecurity and privacy issues).

中医骨伤科学教师教学能力构成要素分析

教师教学能力是教师专业知识技能及个人素养的综合体现,与教学效果紧密相关。中医骨伤科学教师教学能力主要在临床工作和教学实践中养成,反映其课堂授课及临床带教效率和质量,其构成要素应从专业素养、教学设计能力、现代教育技术素养和敬业精神等方面加以强化。